Ground Ring/Counterpoise Sizing

[Keri_WW]

From what I could find, the minimum size for a ground ring/counterpoise around a building is #2 AWG per 250.66(C). I've seen designs utilizing larger wire sizes, typically 3/0. The only thing I could think of was that they were trying to match the size of the grounding electrode conductor.

So how do you actually determine the proper size for the ring?

Thanks,
Keri :grin::grin:

 

[Dennis Alwon]

The code requires no smaller than #2 so you did right. Now if the GEC is 3/0 then the portion that splices out to the ground ring may be #2 but some engineers require 3/0 even to a ground rod. Perhaps there is some benefit for the larger size but I doubt it or the NEC would require it, IMO.